In recent years, the size of portable computers have significantly decreased in size from the original laptop design, to the handheld and subnotebook computers. Handheld computers and subnotebook computers are smaller computers with a laptop type configuration. As the size of these computers have been reduced, the keyboards have as well been reduced in size.
Even though handheld and subnotebook computers that use keyboards are small (e.g. about 3.5".times.7".times.1" for handheld, and about 4.5".times.8".times.1.5" for subnotebook computers), they provide essentially the same functionality of larger laptop computers. For instance, handheld and subnotebook computers run productivity software including word processors, spreadsheets, fax, e-mail, etc. Because of the rapid advancement of computer technology, the capabilities of these smaller computers are constantly increasing. However, there are problems associated with these smaller computers that have been hindering their effectiveness in spite of increasing processing power and an expanding selection of productivity software.
First, regardless of the capability of the hardware and the availability of software for these small computers, their functionality are constrained because they have keyboards that are too small to use effectively and comfortably. In order to use the available productivity software, full keyboard function is essential. Therefore, manufacturers have been attempting to cram full physical keyboards into the footprint area of these small computers. Typically, this means that the keys are small, closely spaced, and some single-key functions are accessed through complex key combinations. Resulting layouts are packed with too many keys that are too cramped to allow adequate keyboard input. Not only are these keyboards tedious to use, they are a bottleneck posing a significant barrier to attaining the potential functionality for handhelds and subnotebooks that manufacturers are trying to provide and that consumers want.
Small screen displays are another constraint on the functionality of subnotebook and especially handheld computers. The effective screen area for these computers is even smaller due to the need to accommodate menu and status bars, which can use up 1/4 to 1/3 of the display area. If this screen "overhead" could be relocated, the effective screen area would increase, significantly improving the functionality of these small computers.
As miniaturization and processors improve, ease of input and effective display area will be increasingly critical factors constraining the use and functionality of handheld and subnotebook computers.
There have been varying efforts to address these problems. For instance, U.S. Pat. No. 5,687,058 to Roylance discloses an apparatus for reducing the dimensions of a computer keyboard for transportation and storage. In its operative position, the keyboard extends beyond the footprint of the computer. In its closed position, the extended keyboard portions are folded such that keyboard sections are vertically adjacent to each other. However, because keyboard sections are placed on top of one another, the thickness of the computer is increased, resulting in a bulkier design. In addition, the keyboard and thereby the computer, are not functional until it is unfolded.
U.S. Pat. No. 5,187,644 to Crisan discloses a compact portable computer having an expandable full size keyboard with extendable supports. The computer includes a housing having a pair of opposing housing compartments therein. The housing compartments are connected by a hinge for permitting selective pivotal rotation of the housing compartments for exposing a pair of inner surfaces corresponding to each compartment. The lower inner surface includes a keyboard having at least one hingedly extendable flap containing a portion of the keyboard. In order to operate the keyboard, the flap must be pivoted away from the inner surface of the lower compartment in order to reveal the remaining keyboard portions. However, there are two major disadvantages to this design. First, the overall thickness of the computer is increased, because the flap must be pivoted on top of the keyboard of the lower compartment for transportation and storage. Second, the keyboard does not become functional until the flaps are pivoted off the main keyboard section.
U.S. Pat. No. 5,267,127 to Pollitt discloses a personal computer with folding and sliding keyboard sections. The keyboard sections are coupled together for pivotal movement about a keyboard axis so that in its opened, operative position, the keyboard overlays the housing of the computer, to a closed position, where the keyboard sections are pivoted about the keyboard axis, whereby the sections of the keyboard are wholly within the outline configuration of the enclosure. While the overall thickness of the computer is not increased, the keyboards are not functional until the sections are properly rotated. In addition, because the sections must ultimately fit within the footprint of the computer, the overall size of the computer is not greatly reduced. Thus, Pollitt is not feasible for smaller handheld or subnotebook computers.
U.S. Pat. No. 5,543,787 to Karidis et al. discloses a keyboard with translating sections. The pallets are movable relative to each other between a compact stowing position and an extended operational position. Upon moving the cover from the open position to the closed position, the pallets are automatically moved from the extended operational position to the compact stowing position. Like Pollitt, because the keyboard sections must fit within the footprint of the computer, the overall size of the computer cannot be greatly reduced. Thus, Karidis is not feasible for handheld computers.
U.S. Pat. No. 5,706,167 to Lee discloses a portable notebook computer having an ergonomically designed keyboard made up of two rotatably separable keyboard sections. The keyboard sections may be manually rotated apart to a desired angle. As the user closes the lid, the sections are automatically driven together. While the feel of the keyboard is somewhat improved, the overall size of the computer is not greatly improved because the keyboard sections must fit within the footprint of the computer.
U.S. Pat. No. 5,644,338 to Bowen discloses an ergonomic laptop computer and ergonomic keyboard. The keyboard is to be used on an operator's lap and separates to relieve stress in an operator's neck and wrists. The keyboard has a flat surface between the keyboard sides, so while being held on a person's lap, will hold reference material and a pointing device that can be used with either hand to keep the neck straight. However, Bowen has no provision for additional keys, nor does Bowen consider relocating any of the QWERTY keys to the flat surface.
Accordingly, there is a need in the art for a keyboard assembly for handheld and subnotebook computers, which provides the effectiveness and comfort of a full-size keyboard without significantly affecting the size or weight of the computer. In addition, there is a need in the art for an expandable display area for subnotebook and handheld computers, which effectively relocates menu bars and status bars to an auxiliary location.